The proposed research aims at: 1) providing developmental data on the relationship between the physical envirionment and behavior, and 2) understanding significant issues in the process of spatial planning. Focusing on a psychiatric hospital for children that has been studied since it opened, the proposal extends the historical picture of the development of space utilization patterns into the current period, adding a study of the ongoing space planning process. In an attempt to relate space utilization patterns to the therapeutic program and the physical design of a facility, the proposal includes: 1) a continuing analysis of the environmental history of the children's hospital using systematic observations (behavioral mapping) and interviews with occupants; 2) a study of privacy in an institutional setting through interviews including comparison with a matched sample of non-institutionalized children. Physical opportunities for privacy are considered through two interventions (placing doors on bedrooms and creating a room for quiet retreat). The effects of these changes on the use of the entire house will be studied through before-and-after observation; 3) providing a record of the process of ongoing spatial planning within the hospital; 4) participation in the planning and evaluation of a new community group residence facility. Included is documentation of the planning and observation of the facility when it opens. 5) Preparation of a final report translating the behavioral findings into design recommendations for children's psychiatric facilities.